PHONONS 89

Heidelberg, 21-25 August 1989Federal Republic of Germany

Proceedings of theThird International Conference on

Phonon Physicsand the

Sixth International Conference onPhonon Scattering

in Condensed Matter

Volume 1

Editors

S Hunklinger W Ludwig G Weiss

UNIVERSITATSEiBLIOTHEK^HANNOVER

TECHNiSCHEi INFORMATiONSB.BLiOTHEK ,

World ScientificSingapore • New Jersey • London • Hong Kong

UNIVERSITA7SBIBLI0THEKHANN0V7.R

TECHNJSCHEINFORM AT.ONSBiBLIOTHEK

VII

CONTENT

32Preface

VOLUME 1

Introductory Remarks: 77 Years of Lattice Dynamics 1

W. Ludwig

Chapter 1: Phonon Dispersion: Theory and Experiments 5

Inelastic Neutron Scattering in Molecular Crystals 7S.F. Trevino

Anharmonic Processes in Molecular Crystals 17B. Perrin

Microscopic Theory of Bulk Phonons in Crystals 27C. Falter

Phonon Dispersion Sheets and Group Velocities in GaAs 37B. Dorner and D. Strauch

Lattice Dynamics of Tin 40A.S. Ivanov, A. Yu. Rumiantsev, N.L. Mitrofanov,B. Dorner and V. V. Pushkarev

Phonon Dispersion in a Deuterated 2,3-DimethylnaphtaleneCrystal at 123 K 43

V.K. Jindal, J. Kalus, U. Scnmelzer, F. Worlen and G. Eckold

First Principles Investigations of Anomalous Phonon Propertiesof Copper Halides 46

J. W. Kremer and K.H. Weyrich

EXAFS Debye-Waller Factors of Agl: Correlation withPhonon Spectra 49

G. Dalba, P. Fornasini, F. Rocca and W. Biihrer

Phonon Frequencies of Copper 52K.K. Chopra and D. Kitous

Phonon Dispersion of the Shape Memory Alloy NiTi 55G. Herget, M. Mullner, G. Eckold and H. Jex

Phonon Density of States of NiTi 58G. Herget, M. Mullner, J.B. Suck, R. Schmidt and H. Wipf

VIII

Phonon Dispersion in Cu-Zn (31 at .%) — "Kohn"-Anomalies and"Short-Range Order Effects 61

W. Buhrer, L. Reinhard, B. Schonfeld and G. Kostorz

Lattice Dynamics and Electro** Phonon Coupling in Copper-BasedAlloys 64

A.S. Ivanov, N.L. Mitrofanov, A.Yu. Rumyantsev,V.A. Udovenko, L. Weiss, H. Eschrig and R. Richter

Lattice Dynamics of Intermediate Valence Semiconductor SmB6 67P.A. Alekseev, A.S. Ivanov, B. Dorner, H. Schober,K.A. Kikoin, E.S. Konovalova, A.S. Mishchenko, V.N. Lazukov,Yu.B. Paderno, A.Yu. Rumyantsev and I.P. Sadikov

Lattice Constant Dependence of the Phonon Spectra ofTransition Metals 70

K. Schwartzman and P.C. Pattnaik

Direct-Space Lattice Dynamics in Metals 73A.K. Sarkar

Phonons in a-Quartz 76B. Dorner, D. Strauch, H. Schober and K. Nutzel

Wavevector Dependence of Phonon Eigenvectors in Si 79D. Strauch, A.P. Mayer and B. Dorner

Phonons in AlSb 82D. Strauch, B. Dorner and K. Karch

Phonon Life Time Spectral Distribution for p-Hydrogen andNaphthalene Crystals 85

E. Sheka, Yu. Shitikov and B. Vindrjayevski

Phonon Modes Investigation with FIR Reflectivity Measurementson One Dimensional Pt-Halogen Chains 88

L. Degiorgi, M. Haruki, P. Wachter and S. Kurita

Far-IR Study of Molecular Beam Deposited Films of theSystem In-Se 91

/. Lelidis, D. Siapkas, J. Emery, C. Julien and M. Balkanski

Light Absorption by Insulating Crystal Films 94K. Arabajian, A.S. Barinov and E.A. Vinogradov

FIR Investigations of Mixed Valence 3d Transition-Metal Oxide(Fe3O4 and Ti4O7) 97

L. Degiorgi, P. Wachter and G. Schlenker

Normal Coordinate Analysis of Model Compounds for Oxidized „Polyacetylene 100

L. Brombacher, A. Hagemeyer and G. Wegner

Investigation of Optical Phonons in AgGaSe2 103J. Camassel, L. Artus, J. Pujol and J. Pascual

Long Wavelength Optical Phonons in ZnTei-x-ySe^SyQuaternary Alloy 106

E.G. Gupta, J. Malhotra and B.B. Tripathi

Interpretation of Optical Peaks in Terms of Critical PointPhonons in Zinc Blende Semiconductors 109

S.S. Kushwaha, S.P. Singh and M.P. Hemkar

Dynamics and Infrared Absorption of Interstitial Oxygenin Silicon 112

W. Kress and S.P. Sanyal

Many-Phonons Absorption of Light in Nonpolar Crystals 115F. V. Kusmartsev

On the Studies of Low-Frequency Excitations in Pigment-ProteinComplexes of Plants by Using Optical Hole-Burning Spectroscopy 118

R. Vladkova

Light Scattering in Thin Films 121E.A. Vinogradov, V.V. Kovalevskii, N.N. Mel'nik andO.A. Turok

Growth Profile Characterization of GaAs Epitaxy on a SiSubstrate. A Micro Raman Study 124

J. Sapriel, J. Chavignon, R. Azoulay, N. Draidia,Y. Gao and H. Boyer

Structure Characterization of CVD and PVD Carbon Films byRaman and IR Spectroscopy 127

M. Wakaki and N. Okuyama

Relations Between Hyper-Rayleigh and Soft-Mode Hyper-RamanScattering in the Incipient Ferroelectric KTaO3 130

H. Vogt

Temperature Behaviour of Low-Frequency Raman Scatteringfrom Lead /3"-Alumina Crystals 133

G. Mariotto, E. Gazzanelli and A. Wague

Raman Study of AlSb 136Y.S. Raptis and E. Anastassakis

Brillouin Scattering in Monoclinic Lithium Sulfate „ 139E. Gazzanelli, A. Fontana and L. Gratton

Phonons in Biology: Brillouin Scattering from Muscle 142N. Berovic, N. Thomas, R.A. Thornhill and J.M. Vaugkan

On Phonon Softening in a Quantum Ferroelectric 145P. Konsin, N. Kristoffel and T. Ord

Inelastic Neutron Scattering from Low Temperature Phases of/9-LiNH4SO4 (LAS) 148

/. Sosnowska, J. Sosnowski and M. Prager

Isotope Effect on NaCl Transverse Optical Phonon Force Constant 151T. Hidaka

Phonon Spectrum of Nickel with Bulk Defect and HighArea Surface 154

P. Nechitaylov, E. Sheka and Yu. Shitikov

Neutron Vibrational Spectroscopy on /9-Tio.84Vo.i6Ho.6i 157I.O. Bashkin, A.I. Kolesnikov, V.Yu. MalyshevE.G. Ponyatovskii, V.K. Fedotov, J. Maier and I. Natkaniec

Resonant Raman Spectra and Photoluminescence in Polythiophene 160J.L. Sauvajol, D. Ghenouni, C. Chorro, B. Moukala andJ.P. Lere-porte

Dynamics of Polythiophene (Perfect and with Defects) —Spectral Moments Method 163

G. Poussigue and C. Benoit

Magnetic Effects in the Elastic Constant C'of bcc Fe(Si) 166J.M. Alves and A.M. Vallera

Phonon Excitations in Heisenberg Magnets 169T.J. Drye and J. W. Tucker

Effect of Energy Bands on Transverse Magnetoresistance inDegenerate n-Type Indium Antimonide 172

C.-C. Wu and J. Tsai

Physical Nature of Phonons and Photons and their Role inConduction and Superconductivity 175

M. Simhony

Phonon Eigenvectors in Shell-Model Description of CubicSilicon Carbide 178

C. Cheng and K. Kunc

Anharmonic Model for Lattice Dynamics in Silicon " 181M.T. Labrot, A.P. Mayer and R.K. Wehner

Reflectivity Spectra of AlaGai_a;As Homogeneous and ModulatedAlloys by a Bond Charge Model, Average T-Matrix Calculation 184

M. Bernasconi, L. Miglio, L. Colombo and G. Benedek

A Bond-Charge Model for the Pseudoatom in Germanium 187M.A. Ball

A New Model for Lattice Dynamics of Noble Metals 190M.M. Shukla, B. Laks and J. Mahanty

A Selfconsistent Calculation of Phonon Frequencies, ChargeDensity and Electronic Bandstructure of Si 193

H. Rakel, M. Klenner, C. Falter and W. Ludwig

Calculation of Electron-Phonon Matrix Elements in Siliconwithin the Partial Density Model 196

M. Klenner, H. Rakel, C. Falter and W. Ludwig

Can Reliable Information be Got from Experimental Phonon Data? 1995. Hajaij and M.A. Ball

Phonons in Substitutional fee Cobalt-Nickel Alloys 202B. Laks, M. Imaizumi and M.M. Shukla

The Macroscopic Polarization of a Zone-Center Transverse Mode 205P. Giannozzi, S.de Gironcoli and R. Resta

Absolute Deformation Potentials in Semiconductors 208R. Resta, L. Colombo and S. Baroni

Lifetimes and Frequency Shifts of Phonons in Si 211S. Narasimhan and D. Vanderbilt

Chapter 2: Phonons in High-Tc Superconductors 215

Lattice Dynamics and Electron-Phonon Coupling in High-TcSuperconductors 217

L. Pintschovius

Phonon Transport in High-Tc Superconductors 227P. Berberich

Low Frequency Excitation Spectra of High Tc Superconductors 237A.J. Sievers, T.W. Noh and S.G. Kaplan

Raman Scattering in High-Tc Superconductors 247C. Thomsen

Lattice Dynamics of the Tl-based Superconductors: »Raman and IR Active Modes 256

A.D. Kulkarni, F. W. de Wette, J. Prade,U. Schroder and W. Kress

Ferromagnetic Clustering and High-Tc Superconductivity 259V. Hizhnyakov and E. Sigmund

Two-Phonon Coherent State in Superconducting Polaron Systems 262H. Zheng

Possible Interplay of Intrinsic Doping and LatticeAnharmonicity in HTSC's 265

H. Eschrig and S.-L. Drechsler

Electron-Phonon Interaction and Superconductivity inBa^Ki-jBiOa 268

M. Shirai, N. Suzuki and K. Motizuki

Lattice Dynamical and Quantum-Mechanical Investigationof the Ferroelectric and Superconducting Properties ofBaPbx-sBisOa 271

H. Buttner, A. Bussmann-Holder, A. Simon and V. Waas

Phonons in High-Tc Superconductors 274H.C. Gupta

Pseudo Jahn-Teller Pairing Mechanism in Cuprate Superconductors 277B. Halperin, R. Englman and M. Weger

Phonon Induced Superexchange and Superconductivity of Diholonsand Didublouns in HTSC 280

A.N. Kocharian and P.S. Ovnanian

High-Tc Superconductivity induced by Interband Interaction 283P. Konsin, N. Kristoffel and T. 3rd

About Mechanism of High-Temperature Superconductivity 286F.V. Kusrriartsev, V.I. Levashev and F.D. Senchukov

On the Role of Breathing Phonon in High-Tc Superconductors 289E. Matsushita

Percolation Induced Conductivity in High-Tc SuperconductingMaterials 292

V. Hizhnyakov, N. Kristoffel and E. Sigmund

Pairing Mechanism Driven by a Deformational Coupling withOptical Phonons 295

M. Schneider, E. Sigmund and V. Hizhnyakov

A Model of Phonon Mediated High-Tc Superconductivity - 298T. Sota and K. Suzuki

The Electron-Phonon Interaction in Lai.85Sr0.i5CuO4 301M. Nakatani, T. Sota and K. Suzuki

Isotopic Effect for Tc and Soft Anharmonic Modes 304A.P. Zhernov

High-Frequency Phonon Hardening in Doped YBa2Cu307 andBi2Sr2(Cai_IYI)Cu2O8 as Tc Decreases: An InelasticNeutron Scattering Study 307

F. Gompf, B. Renker, P. Adelmann, D. Ewert,E. Gering and H.Mutka

Experimental Investigation of the Partial Density of Cu AtomsVibrational States for YBa2Cu3O7_y 310

P.P. Parshin, M.G. Zemlyanov, O.E. Parphenovand A.A. Chernyshev

Phonon Intensity Anomalies near 235 K in YBa2Cu3O7_;,;Superconductors: Reconciliation of the Results of Zhang et al.and of Rebane et al. 313

J.F. Scott and Zhang Ming-sheng

Thermal Conductivity of High-Tc Ceramics 316V.B. Efimov, A.A. Levchenko, L.P. Mezhov-Deglin,R.K. Nikolaev, N.S. Sidorov and I.E. Schtinov

Two Level Tunneling Systems as a Probe of Electrons and Phononsin the High Tc Superconductor YBa2Cu307_d and in Niobium 319

C. Elbaum, M.J. McKenna, A. Hikata, R. Kershaw andA. Wold

Ultrasonic Studies of Two Level Systems and their Relationto Oxygen Content and Tc in YBa2Cu307_« 322

A. Hikata, M.J. McKenna, C. Elbaum, R. Kershaw andA. Wold

Glassy Behaviour of Low Temperature Energy Relaxation inYBa2Cu307 and YBa2Cu306 325

A. Sahling and S. Sahling

Fabrication of Thin-Film High-Tc Superconductors:Application as a Phonon Detector 328

M. Obry, J. Tate, P. Berberich and H. Kinder

FIR Study of the YBa2Cu306 Phonon Anisotropies 331I.B. Ferreira, M. Bauer, L. Genzel, P. Murugaraj and J. Maier

XIV

Theory of Interband Raman Scattering in.YBa2Cu3O7:a Probe of Unconventional Superconductivity 334 j

H. Monien and A. Zawadowski

Raman Scattering on all of Possible Phonon Modes in High-TcYBa2Cu307_a; 337

S.L. Zhang, Y. Jin, Z.-A. Guo, G.-C. Xiong, S.-Z. Wang

Optical Phonons in Superconductor Bi2Sr2CaCu2O8+x:Polarized Raman Spectra and Complete Theoretical Analysis ofOrthorhombic Structures 340

A.A. Bush, I.V. Gladishev, A.A. Golub, M.F. Limonov,Yu.F. Markov, O. Yu. Mashtakov, V. Yu. Mirovitskii,G.V. Mikhailov and A.G. Panfilov

Anomalous Angular Dependence of the Ag-Phonon Intensities andSoft Mode in the La2-aSraCuO4 Crystals 343

V.N. Denisov, A.F. Goncharov, B.N. Mavrin,V.B. Podobedov

Resonant Raman Scattering in High Tc Superconductors 346E.T. Heyen, R. Liu, B. Gegenheimer, C. Thomsen, <M. Cardona, S. Pinol and D. MckPaul

Raman Active Phonons in the High-Tc Superconductors: iA Global Point of View 349

G. Burns, M.K. Crawford, F.H. Dacol, N. Herron and jF. Holtzberg '•

Far Infrared Spectroscopy of Phonons in High Tc Superconductors 352 ;M.K. Crawford, G. Burns, E.M. McCarron, W.E. Farneth,F. Holtzberg and N. Herron I

Characterization of the Bidimensionality of Electronic ,Properties in High-Tc Superconductors by Infrared ;Reflectivity Spectfoscopy 355 ij

F. Gervais, P. Echegut, J.M. Bassat, M. Gervais, ['K. Dembinski and P. Odier J

Temperature Dependent Far Infrared Studies of Magnetically- ?Oriented YBa2Cu307_« 358 ,̂

C.H. Perry, F. Lu, K. Chen and R.S. Markiewicz \

Evidence of Free Carrier Localization in the Phonon Spectra ofYBa2Cu30a! 361

V.M. Burlakov, K.V. Kraiskaya, A.G. Mitko, iE.A. Firsov and V.A. Yakovlev

Chapter 3: Phonons and Low-Energy Excitations JnAmorphous Solids 365

Vibration and Relaxation in Glasses 367W.A. Phillips

Extensions of the Tunneling Model 375D.A. Par shin

Low-Frequency Vibrational Spectra of Amorphous Solids 387W.A. Kamitakahara

Atomic Dynamics of Icosahedral Alloys 397J.-B. Suck

Glasses and Crystalline Defect Systems at Low Temperatures:Dielectric Experiments 407

M.v. Schickfus, G. Baier and C. Enss

Low Lying Instability of a Distorted Octahedron: Model forTunneling in Glasses 417

H.R. Schober, U. Buchenau

Correlation Time Measurement of the Pseudo-MagnetizationFluctuations in an Amorphous Compound 420

M. Devaud, J.-Y. Prieur

Acoustic Experiments at Ultralow Temperatures on AmorphousPdSiCu 423

P. Esquinazi, R. Konig, F. Pobell, F. Dietzel,G. Weiss, S. Hunklinger

The Phonon — Phonon Interaction Induced by Two LevelSystems in Glasses 426

V.S. Lutovinov

Specific Heat of Rare-Gas Films at Low Temperatures 429H. Menges, R. Rapp, N. Steinmetz, A. Goldacker andH.v. Lohneysen

An Interacting Defect Model of Amorphous Materials 432Glare C. Yu and A.J. Leggett

Low-Temperature Specific Heat of Glasses: Quantum Monte CarloSimulation of a Strongly Anharmonic Oscillator 435

J. Michalski and P. Erdos

A Librational Mesoscopic Soft Mode Model of Glasses 438M. Wagner and Th. Mougios

XVI

I

Simple Microscopic Models for Disordered Structures: •»

Two Level Systems and Specific Heat 441 |

R. Schilling |

Vibrat ional States and Tunneling in Irradiated Crystals I

and in Glasses 444

H.R. Schober

High Resolution Brillouin Scattering from Vitreous Silica

at High Pressures and Low Temperatures 447 I

D. Tielburger, R. Merz and S. Hunklinger *

Anharmonicity Versus Thermally Activated Structural Relaxation

in Crystalline, Amorphous and Irradiated SiO2 450

J.P. Bonnet, A.A. Gherbi, M. Boissier, R. Vacher, \

J. Pelous, A. Vanelstraete and C. Laermans

The Theory of Low Temperature Electric Dipole Echo f

in Glasses 453 t

V.L. Gurevich, M.I. Muradov and D.A. Parshin I

Nonlinear Low-Temperature Absorption of Ultrasound and \

Electromagnetic Waves in Glasses 456 I

Yu.M. Galperin, D.A. Parshin and V.N. Solovyev J

Monte-Carlo Simulation of Spectral Diffusion in Glasses: *

Nonlinear Resonant Attenuation and Hole Burning 459 ;

D.A. Parshin and V.N.Solovyev f.

Numerical Simulation of Echo Phenomena in Dielectric

Glasses 462

D.A. Parshin, A.S. Polhovskii and V.N. Solovyev

The Nonlinear Regime of Sound Damping Due to Relaxational

Absorption in Glasses 465

V. Lutovinov

Low Temperature Heat Release in Glasses 468M. Deye and P. Esquinazi

Low-Temperature Elastic Properties of Amorphous

(Moi-sRu^o.sPo^ 471F. Lichtenberg, H. Raad, W. Morr and G. Weiss

Dynamics of Tunneling States in Borosilicate Glass 474C. Enss, C. Bechinger and M.v. Schickfus

Density of Tunneling States in Electrolyte Glasses 477V. Rohring, K. Runge and G. Kasper

Evolution of Solid State Amorphization during Mechanical •»

Alloying of PdSiCu 480

M.J. McKenna, A. Hikata and C. Elbaum

Acoustic Measurements of Quench-Condensed Ar-Xe-Mixtures 483

L. Hornig, B. Dottling, G. Weiss, S. Hunklinger and

F.Baumann

Structure and Specific Heat of Quench-Condensed Rare-Gas

Mixtures 486

R. Dorwarth, J. Hasse, H. Menges and H.v. Lohneysen

The Low-Temperature Ultrasonic Attenuation and the PhononMechanisms in Neutron Irradiated Quartz 489

V. Esteves, C. Laermans

Precision Ultrasonic Velocity Measurements in NeutronIrradiated Quartz Upon Heat-Treatment 492

C. Laermans, A. Vanelstraete

High Frequency Phonon Transmission Through Amorphous Films 495J. Mebert, B. Maile, W. Eisenmenger

Picosecond Optics Measurement of Attenuation of HighFrequency Phonons in a-SiO2 498

C.-D. Zhu, H.J. Maris and J. Tauc

Lattice Vibrations in Glasses at High Temperatures 501D.G. Cahill, S.K. Watson, R.O. Pohl

Elementary Structure Rearrangements at Boundaries in aPolycluster Amorphous Solid and their Contribution toInternal Friction 504

A.S. Bakaj and N.P. Lazarev

Thermal Conduction Threshold in Binary ChalcogenideGlasses 507

J. Philip, K.N. Madhusoodanan, E.S.R. Gopal and S.Asokan

Temperature Dependence of Thermal Diffusivity in Ge-Se andAs-Se Glasses 510

K.N. Madhusoodanan and J. Philip

Is the Thermal Conductivity of Undercooled Melts Near theGlass Transition (and of Glasses) Frequency Dependent? 513

J. Jackie

Low Temperature Long-Time Energy Relaxation in LiCl*7H2O 516S. Sahling

XVIII

Anelastic Relaxations in Rare Earth Phosphate Glasses v 519G. Carini, M. Cutroni, G. D'Angelo, M. Federico,G. Galli, G.A. Saunders and G. Tripodo

Vibrational Decoupling of the Symmetric Ring Mode inVitreous B2O3 522

M.A. Kanehisa and R.J. Elliott

Unusual Temperature Dependence of Nuclear Spin Relaxationin Fluoride Glasses at Low Temperatures 525

S. Estalji, O. Kanert, J. Steinert,G. Balzer-Jollenbeck and H. Jain

Universal Form of the Low-Energy Vibrational Spectrumof Glasses 528

V.K. Malinovsky, V.N. Novikov, P.P. ParshinA.P. Sokolov and M.G.Zemlyanov

Effective Medium Theory for Phonons Glasses: The MeanFree Path 531

W. Schirmacher and M. Wagener

The Soft Mode Concept as a Link Between Entropy of Liquidsand Tunneling States in Glasses 534

U. Buchenau

Neutron Scattering Determination of the Vibrational Spectraof Amorphous and Crystalline H2O Ice 537

E.C. Svensson, V.F. Sears, J.H. Root, C. Szornel,D.D. Klug, E. Whalley and E.D. Hallman

Inelastic Neutron Scattering Study of a Ternary TransitionMetal-Metalloid Glass 540

R. Caciuffo, O. Francescangeli, S. Melon, E. Gering,J.-B. Suck, M. Bonnet

Experimental Observation of Soft Anharmonic Modes inZr67Cu33 Metallic Glass 543

G.F. Syrykh and A.P. Zhernov

Multiphonon Absorption and the Phonon Sideband in theAbsorption of Hydroxyl Vibrations in Fused Silica 546

A.R. Silin

Raman Scattering from Disordered SiC 549S. Nakashima, H. Ohta and M. Hangyo

Theory of Direct Determination of Phonon-Induced PhaseRelaxation by Two-Step Pulsed Spectral Hole Burning 552

/. Re bane

XIX

Persistent Spectral Holes in Disordered Systems: A Probe ofBarrier Crossing in Double-Well Potentials 555

T. Attenberger, K. Beck and U. Bogner

Optical Heating of Dielectric Glasses: Hole-Burning Study 558A.A. Gorokhovskii, G.S. Zavt and V.V. Palm

Phonon Spectra and Green Functions in a Variety ofFibonacci Lattices . 561

M. Goda, H. Kubo and H. Yamada

Metastable High Pressure Quenched Fee Al-Si Solid Solution 564J. Chevrier, J.B. Suck, J.C. Lasjaunias,J.J. Capponi and M. Perroux

Vibrational Properties of Fibonacci Chains 567H. Bottger and G. Kasner

Vibrational Localization and Thermal Conductivity of aClassical Model of a Two-Dimensional Quasicrystal 570

J. Michalski and P. Erdos

Icosahedral, Glassy and Crystallized AI75CU15V10:A Comparative Study of Their Generalized VibrationalDensity of States 573

J.-B. Suck and H.-J. Guntherodt

A Comparative Study of the Lattice Dynamics of AlCuLi inthe Crystalline R-Phase and the T2-Phase 576

J.-B. Suck, C. Janot, M. de Boissieu and B. Dubost

Elastic Mysteries: Disorder and the Low-Temperature Behaviorof Mechanical Oscillators 579

J.E. van Cleve, J. Chevrier and R.O. Pohl

Glass-Like Lattice Vibrations in Mixed Crystals 582S.K. Watson, D.G. Cahill and R.O. Pohl

Low Temperature Specific Heat in the Orientational Glass(NaCNJi-^KCN)* 585

B. Mertz, R. Bohmer, A. Loidl, J.F.Berret,M. Meissner and W. Knaak

Non-Ergodic Instability and Phonon Damping at anOrientational Glass Transition 588

K.H. Michel and C. Bostoen

Reorientation of Pairs of Coupled XYe Centres inAlkali Halide Crystals 591

T. Kranjc

XX

Soft Phonons and Central Peak in the Orientational Glass

XXI

Chapter 4: Excitations in Fractal Structures •> 633

Fracton Dynamics of Fractal Structures 635R. Vacher and E. Courtens

New Aspects of Fracton Dynamics from SupercomputerSimulations 646

T. Nakayama

Low-Frequency Vibrational Density of States ofSilica-Aerogels 656

G. Reichenauer, U. Buchenau, H. Conrad,B. Frick and J. Fricke

Excitations on Fractal Structures: Thermal Properties ofSilica Aerogels 659

B. Sake, R. Calemczuk, R. Maynard

Scaling of Higher Order Elasticity in Fractal Aerogels 662P. Xhonneux, E. Courtens, T. Woignier, J. Pelousand R. Vacher

Low-Temperature Thermal Conductivity of Silica-Aerogels 664P. Scheuerpflug, H.-J. Morper, G. Neubert and J. Fricke

Neutron Scattering from Silica: Aerogels, Cabosil andAmorphous Bulk Glass 667

J.H. Page, D. W. Schaefer, J.H. Root, W.J.L. Buyers,C.J. Brinker

Low Frequency Vibrational Modes at the Particle Scale inSilica Aerogels 670

J.L. Sauvajol, J. Pelous, R. Vacher and T. Woignier

Dielectric Long Time Relaxation of PLZT 673R. Ho'hler, G. Kasper, A. Sternberg and A. Krumins

Vibrational Modes in Elastic Percolation Systems 676H. Bottger, A. Freyberg and D. Wegener

Ultrasonic Velocity and Attenuation in a Glass-BeadPercolation System 679

N. Pachet and J.H. Page

Vibrational Density of States of Vector Fractons 682K. Yakubo and T. Nakayama

Test of Scaling for the Vibrational Density of States ofPercolating Systems 685

S. Russ, H.E. Roman and A. Bunde

XXII

Rigidity Percolation in Sei-xGea; Glasses * 688J. Y. Duquesne and G. Bellessa

Fractons in Polymers: Comparative Study by Neutron andRaman Scattering 691

V.K. Malinovsky, V.N. Novikov, P.P. Parshin,A.P. Sokolov and M.G. Zemlyanov

Lattice Vibrations of the Diluted Two^Dimensional CooperativeJahn-Teller System K2Cu3;Zn1_:rF4 694

/. Yamada, Y. Fukada and M. Totani

Neutron Scattering Results on the Density of States ofFractals 697

G. Coddens, J. Pelous, T. Woignier, R. Vacher,E. Courtens and J. Williams

VOLUME 2

Chapter 5: Phonons In Super lattices and Quantum Wells 701

Phonon Transmission through Periodic, Quasiperiodic andRandom Superlattices 703

S. Tamura

Confinement Effects on Free Carrier Scattering fromOptical Phonons in Semiconductor Quantum Wells 713

R. Haupt, L. Wendler, F. Fiedler and F. Bechstedt

Lattice Dynamics of GaSb/InAs Superlattices in aBond-Charge-Model Approach 716

L. Colombo and L. Miglio

Frequency Gaps in Acoustic Phonon Transmission in Periodic,Quasiperiodic and Real Superlattices for Normal Incidence 719

R. Hotz

Disorder Effects on the Phonon Spectra of UltrathinSemiconductor Superlattices: First Principles Results 722

5. Baroni, P. Giannozzi and E. Molinari

Relationship of Microscopic and Macroscopic Theories forOptical Phonons in GaAs-AlAs Superlattices 725

F. Bechstedt, H. Gerecke and L. Wendler

Theory of Phonon-Polariton Modes in Low Dimensional Structures 728N. Raj, D.R. Tilley, T. Dumelow and T.J. Parker